The present invention relates to a counterbalancing unit. More particularly, the present invention relates to a simple counterbalancing unit for a tripod head capable of generating an appropriate amount of a restoring force in proportion to a torque created while a tripod head is tilted. The unit also allows a photographing device, such as a camera, a video camera or a movie camera, mounted on a tripod head to tilt stably and smoothly. This invention also relates to a counterbalancing unit capable of easily adjusting the restoring force corresponding to various weights of the photographing device.
A tripod head has been conventionally used as a device for fixing a photographing device such as a camera, a video camera or a movie camera on a tripod and for realizing smooth tilting rotation of the photographing device.
A counterbalancing means is incorporated in such a tripod head for preventing the photographing device from quickly rotating and falling when it is tilted downward.
This counterbalancing means is a means in which a restoring force is generated by an elastic body such as a spring in proportion to a torque due to transference of the center of gravity of the photographing device. The restoring force prevents the photographing device from falling and allows it to be tilted stably and smoothly.
A counterbalancing means for a tripod head is disclosed in Japanese Publication No. 27560/90 and Japanese Utility Model Publication No. 13037/91, for example. A crank or cam, each of which rotates eccentrically in accordance with the tilting rotation of the tripod head is applied to the means described in those publications. However, numerous elements have to be considered in a design of the above counterbalancing means. Therefore, the design work is very complex. Further, since the counterbalancing means is a complicated structure, it is expensive to manufacture and the operation thereof is not necessarily satisfactory.